Transmission Shifting issues - A442F Transmission Solenoids Replacements

[therestevethedog]

Tested voltage between E1 and TT

• it does vary with throttle position

Disconnected Solenoid wire from transmission case and road test

• Manually shifts between gears as expected.

Reconnect solenoid wire and tested voltage between E1 and TT during road test. All voltages check out.

• 1st - 0.333v
• 2nd - 2v
• 3rd - 4v
• 3rd lock-up - 5v
• OD - 6v
• OD lock-up 7v

Although I didn't bench test the solenoids, I have a hard time believing it's a bad one since it's showing the exact same behavior with a brand new set.

I'm done for today. Tomorrow I'll check the voltages on the TCM per the manual.

 

[Malleus]

A new solenoid can be bad; that's why Toyota insists on test records from their vendors.

 

[therestevethedog]

Understood, but the likelihood that the original and new are faulty in the same position and the same way is pretty low. I’ll bench test the old ones tomorrow to be sure at least of that.

The behavior really seems like it is electronics related. Once it’s shifted from L or R to D it doesn’t have any issues at all. It’s like shifting directly to D doesn’t trigger the gear to shift initially.

Anyway, more testing coming up.

 

[SmokingRocks]

You're doing great keep going. I know its frustrating but when you figure it out you're going to feel elated that you tracked it down via the true mechanics diagnostic tree. You'll also learn a lot.

 

[SmokingRocks]

Im more worried about the solenoids actually getting signal to operate, you may have an electrical issue between the trans brain and the solenoid preventing the solenoid from receiving the signal to actuate. I'm not looking at the EWD right now so just a hunch but it could be on point. There is are a group of connectors by the starter that are common issue spots, where if water gets in it can create corrosion and bad contacts. This is the electrical path that all the transmission controls run through.

 

[SmokingRocks]

ECT functioning propperly means the transmission is getting power and signal. Did this happen before you replaced the filter?

Have you pulled your engine codes? some may be on without illuminating the CEL.

I'm thinking there is a communication issue between the ECU, TCU and transmission when selecting drive, so I'd focus on that electrical pathway

 

[SmokingRocks]

Have you located your transmission control unit (drivers footwell left). Its worth checking continuity on the runs that span between that and the end plugs on the trans.

 

[mjosoba]

Hey @SmokingRocks could this be a NSS issue?

 

[therestevethedog]

I'm not getting any engine codes. I've got the panel off the footwell and the voltage testing chart for the TCM, so that's what I plan to run through later this morning. I'll also check continuity between the TCP and the solenoid wire harness as well as inspect the connection bundle by the starter. Hope I can get to the bottom of this today.

 

[therestevethedog]

So I ran through testing all the voltages on the TCM and found several issues. I double checked all these 'bad' points. They're definitely faulty. Seems to me the TCM itself is failing. I'm going to crack it to see if there are any obvious leaking caps or cracked solder joints.

• S2 - GND in Neutral
  • Expected 9-14V
  • Measured 0v
• ECT1 - GND
  • Expected 9-14V
  • Measured 127mV
• P - GND in P Position
  • Expected 7.5-14V
  • Measured 10mV
• N- GND in N Position
  • Expected 7.5-14V
  • Measured 20mV

Anybody live near Woodland Hills, CA and feel up for a TCM swap to test LOL?

 

[therestevethedog]

So I got in to the NSS harness and gave it a good look. Holy smokes that's awkward to reach! Is there a way to get in there without having noodle arms?

It's dirty but doesn't look invaded or corroded from a PHH leak. I do need to replace that hose though. Project for another day.

In any case, after essentially jiggling and reseating those connectors I started the truck and the P and N lights are working. So I rechecked the voltages that were wrong and they are all in range now. 12v solid for S2, ECT1, P, and N now. Tested shifting directly from P to D and the transmission engages properly.

So next up, I have to properly get into the NSS harness and inspect the whole thing, and do the PHH.

Thanks so much for encouragement and guidance! Love it.

 

[SmokingRocks]

Put a WTB thread in the classifieds for a replacement TCU, there have been cases where they have failed and I bet you could pick a used one up for $40 +/-. Cheap spare to have on hand if nothing else.

 

[SmokingRocks]

Regarding your test:

• S2-Gnd fault indicates a solenoid #2 issue
  • Either Solenoid #2 is faulty or the pathway shown here is compromised
  • 
• ECT1-GND Undervoltage indicates a fault with this pathway
  • 

Both of the first two faults go through connector IH3 so I would highly suspect that there is a continuity issue at IH3


Your issues with P-GND & N-GND both indicate a fault in the IH2 connector or faulty A/T Indicator Switch (NSS)

 

[SmokingRocks]

Yea the harness is a PITA there, if you take your trans cross member off and lower your trans using a floor jack you can get better access to the harness.

 

[therestevethedog]

@SmokingRocks , I can't thank you enough for your feedback and help with this. Could not have gotten here on my own.

This weekend the wheel is coming off and I'm replacing the knock sensor that disintegrated when I touched it. Gonna see if that gives me enough access to check, clean, and reseat all of the harness connections in there.

Cheers!

 

[SmokingRocks]

Glad I can help, I know how frustrating electrical issues are to troubleshoot.

Re: knock sensors, only use toyota genuine. SERIOUSLY aftermarket ones WILL NOT WORK.

 

[thebovees]

Got mine ordered from a place/part number post on this site. Like $30 total amd they worked great. Came in a box that was labeled "Izuzu"

Are all four solenoids the same?

 

[bug616]

Are all four solenoids the same?

No

 

[xetura]

So I got in to the NSS harness and gave it a good look. Holy smokes that's awkward to reach! Is there a way to get in there without having noodle arms?

It's dirty but doesn't look invaded or corroded from a PHH leak. I do need to replace that hose though. Project for another day.

In any case, after essentially jiggling and reseating those connectors I started the truck and the P and N lights are working. So I rechecked the voltages that were wrong and they are all in range now. 12v solid for S2, ECT1, P, and N now. Tested shifting directly from P to D and the transmission engages properly.

So next up, I have to properly get into the NSS harness and inspect the whole thing, and do the PHH.

Thanks so much for encouragement and guidance! Love it.

I recently replaced my NSS and ended up having to replace the connectors. The connector was so badly corroded, the connections inside disintegrated when being removed. Upon first glance, it looked like I could clean them, but I quickly realized that wasn't the case. My transmission also acted weird before I fixed the connector and wouldn't stay in low. Once I re-wired it (Deutsch connector), it acted like it should and stayed in gear. And all my dash gear lights work again!

 

[Jimmyrios]

Hi everyone...need some advice...urgently....shifthing problems with my 442f transmition made me resarch with my autodiagnostic tranny tool found out solenoids failing codes, took of the pan got out all 4 solenoids, performed the resistance test and all of them are showing 12.7 ohms seems fine, but when I apply 12 volts to all of them, none make no noise or Cliking at all ? They block the air, when you apply air to them (air test) but NO CLICKING AT ALL. ARE THEY FAILING???
ALSO, has anyone attemped to reacondition them? Thank you